1. Field of the Invention
This invention generally relates to instrumentation for use in the field of measurement of radioactive materials, and more particularly relates to instrumentation for the use thereof in the field of Medicine.
2. Prior Art
The medical use of radioactive materials for both diagnostic and therapeutic purposes is well recognized, known and documented, and has been an accepted standard practice in most hospitals for many years. When using radioactive materials from a multidose container, the determination of the volume to withdraw for a desired patient dose is complicated by various factors such as the half-life of the radioactive material, the energy of the material, the volume of the container, and the attenuation of the gamma rays by the container walls. One method used is to place the source container in a well-type detector of an electronic device called a dose calibrator. If this dose calibrator device has been properly calibrated and adjusted to compensate for the energy of the isotope and attenuation due to the container walls, it will provide a reading of the radioactivity of the material contained therein. With this premise, if the technologist knows the volume of the contained radioactivity, a calculation of the concentration can be made, and the volume required for the patient dose may be determined. Among the drawbacks to this method are that the container holding the radioactive material must be removed from its leaded radiation shield thereby subjecting the operator to a radiation hazard, and that this procedure entails several mathmatical calculations. Since both dose withdrawal and half-life of the source affect the remaining amount of radioactivity, a record of withdrawals, with respect to time and quantity, must be maintained for each successive calculation or determination.
Thus, because of the radiation hazard, complexity of calculations and attendant record keeping, a novel device for storing radioactive materials, having provision for determining both the concentration and the volume required for a patient dose, and for removal of said material from its container would be useful in the nuclear medicine department of all hospitals or other facilities engaged in similar activities.